1. Field of the Invention
The present invention relates to a rotary electric machine of the type having a liquid-cooled rotor, such as a turbine generator, and more specifically to a rotary electric machine of the type having a liquid-cooled rotor in which the construction of the connection between the generator shaft and the exciter shaft is improved.
2. Description of the Prior Art
In the rotary electric machines of the type, shafts rotatable around a common axis are used for both the exciter and the generator, and a rectified DC voltage from the exciter is applied to the field coil of the generator. For this purpose, therefore, a device is necessary to mechanically and electrically couple the exciter and the generator together.
The existing connection between the generator shaft and the exciter shaft in a rotary electric machine of the type having a liquid-cooled rotor, consists of; a junction portion between the generator shaft and the exciter shaft, a junction portion between a coolant path of the generator shaft and a coolant path of the exciter shaft, and a connection portion for electric circuits, wherein the junction portions and the connection portion are located in one place relative to the length direction of the common axis. Therefore, construction tends to become complicated, and the space for the junction portions and the connection is rather limited. Consequently, the cooling liquid often leaks, poor electrical connection creates increased contact resistance which gives rise to the development of heat which can destroy the machine, and subsequently, reliability is decreased.